This document describes the recommended coding style for kdelibs. Nobody is forced to use this style, but to have consistent formatting of the source code files it is recommended to make use of it.

This document describes the recommended coding style for kdelibs. Nobody is forced to use this style, but to have consistent formatting of the source code files it is recommended to make use of it.

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'''In short: Kdelibs coding style follows the Qt 4 coding style.'''

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<!--T:2-->

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'''In short: Kdelibs coding style follows the [http://wiki.qt-project.org/Coding_Style Qt 4 coding style], with one main difference: using curly braces even when the body of a conditional statement contains only one line.'''

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== Indentation ==

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== Indentation == <!--T:3-->

* No tabs

* No tabs

* 4 Spaces instead of one tab

* 4 Spaces instead of one tab

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== Variable declaration ==

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== Variable declaration == <!--T:4-->

* Each variable declaration on a new line

* Each variable declaration on a new line

* Each new word in a variable name starts with a capital letter (so-called camelCase)

* Each new word in a variable name starts with a capital letter (so-called camelCase)

Line 13:

Line 17:

* Take useful names. No short names, except:

* Take useful names. No short names, except:

** Single character variable names can denote counters and temporary variables whose purpose is obvious

** Single character variable names can denote counters and temporary variables whose purpose is obvious

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** Variables and functions start with a lowercase letter

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* Variables and functions start with a lowercase letter

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<!--T:5-->

Example:

Example:

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</translate>

<syntaxhighlight lang="cpp-qt">

<syntaxhighlight lang="cpp-qt">

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// wrong

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<translate><!--T:6-->

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// wrong</translate>

KProgressBar *prbar;

KProgressBar *prbar;

QString prtxt, errstr;

QString prtxt, errstr;

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// correct

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<translate><!--T:7-->

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// correct</translate>

KProgressBar *downloadProgressBar;

KProgressBar *downloadProgressBar;

QString progressText;

QString progressText;

QString errorString;

QString errorString;

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</code>

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</syntaxhighlight>

−

== Whitespace ==

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<translate>

+

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== Whitespace == <!--T:8-->

* Use blank lines to group statements

* Use blank lines to group statements

* Use only one empty line

* Use only one empty line

Line 34:

Line 44:

* No space after a cast

* No space after a cast

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<!--T:9-->

Example:

Example:

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</translate>

<syntaxhighlight lang="cpp-qt">

<syntaxhighlight lang="cpp-qt">

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// wrong

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<translate><!--T:10-->

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// wrong</translate>

QString* myString;

QString* myString;

if(true){

if(true){

}

}

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// correct

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<translate><!--T:11-->

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// correct</translate>

QString *myString;

QString *myString;

if (true) {

if (true) {

}

}

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</code>

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</syntaxhighlight>

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== Braces ==

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<translate>

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== Braces == <!--T:12-->

As a base rule, the left curly brace goes on the same line as the start of the statement.

As a base rule, the left curly brace goes on the same line as the start of the statement.

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<!--T:13-->

Example:

Example:

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</translate>

<syntaxhighlight lang="cpp-qt">

<syntaxhighlight lang="cpp-qt">

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// wrong

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<translate><!--T:14-->

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// wrong</translate>

if (true)

if (true)

{

{

}

}

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// correct

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<translate><!--T:15-->

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// correct</translate>

if (true) {

if (true) {

}

}

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</code>

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</syntaxhighlight>

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<translate>

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<!--T:16-->

Exception: Function implementations, class, struct and namespace declarations always have the opening brace on the start of a line.

Exception: Function implementations, class, struct and namespace declarations always have the opening brace on the start of a line.

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<!--T:17-->

Example:

Example:

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</translate>

<syntaxhighlight lang="cpp-qt">

<syntaxhighlight lang="cpp-qt">

void debug(int i)

void debug(int i)

Line 74:

Line 97:

{

{

};

};

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</code>

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</syntaxhighlight>

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<translate>

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<!--T:18-->

Use curly braces even when the body of a conditional statement contains only one line.

Use curly braces even when the body of a conditional statement contains only one line.

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<!--T:19-->

Example:

Example:

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</translate>

<syntaxhighlight lang="cpp-qt">

<syntaxhighlight lang="cpp-qt">

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// wrong

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<translate><!--T:20-->

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// wrong</translate>

if (true)

if (true)

return true;

return true;

Line 87:

Line 115:

qDebug("%i", i);

qDebug("%i", i);

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// correct

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<translate><!--T:21-->

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// correct</translate>

if (true) {

if (true) {

return true;

return true;

Line 95:

Line 124:

qDebug("%i", i);

qDebug("%i", i);

}

}

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</code>

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</syntaxhighlight>

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== Switch statements ==

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<translate>

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== Switch statements == <!--T:22-->

Case labels are on the same column as the switch

Case labels are on the same column as the switch

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<!--T:23-->

Example:

Example:

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</translate>

<syntaxhighlight lang="cpp-qt">

<syntaxhighlight lang="cpp-qt">

switch (myEnum) {

switch (myEnum) {

Line 113:

Line 145:

break;

break;

}

}

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</code>

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</syntaxhighlight>

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== Line breaks ==

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<translate>

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== Line breaks == <!--T:24-->

Try to keep lines shorter than 100 characters, inserting line breaks as necessary.

Try to keep lines shorter than 100 characters, inserting line breaks as necessary.

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== Qt Includes ==

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== Qt Includes == <!--T:25-->

* If you add #includes for Qt classes, use both the module and class name. This allows library code to be used by applications without excessive compiler include paths.

* If you add #includes for Qt classes, use both the module and class name. This allows library code to be used by applications without excessive compiler include paths.

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<!--T:26-->

Example:

Example:

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</translate>

<syntaxhighlight lang="cpp-qt">

<syntaxhighlight lang="cpp-qt">

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// wrong

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<translate><!--T:27-->

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// wrong</translate>

#include <QString>

#include <QString>

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// right

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<translate><!--T:28-->

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// correct</translate>

#include <QtCore/QString>

#include <QtCore/QString>

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</code>

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</syntaxhighlight>

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== Artistic Style (astyle) automatic code formatting ==

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<translate>

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== Artistic Style (astyle) automatic code formatting == <!--T:29-->

You can use [http://astyle.sourceforge.net/ astyle] (>=1.23) to format code or to test if you have followed this document. Run the following command:

You can use [http://astyle.sourceforge.net/ astyle] (>=1.23) to format code or to test if you have followed this document. Run the following command:

A related shell script could be found for unix in [http://websvn.kde.org/*checkout*/trunk/KDE/kdesdk/scripts/astyle-kdelibs kdesdk/scripts/astyle-kdelibs] and for windows in [http://websvn.kde.org/*checkout*/trunk/KDE/kdesdk/scripts/astyle-kdelibs.bat kdesdk/scripts/astyle-kdelibs.bat].

The "scripts" directory in the kdesdk module contains, among other useful things, some useful additions to the Emacs and Vim text editors that make it easier to edit KDE code with them.

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The [https://projects.kde.org/projects/kde/kdesdk/kde-dev-scripts/repository/revisions/master/show kde-dev-scripts] directory in the kdesdk module contains, among other useful things, some useful additions to the Emacs and Vim text editors that make it easier to edit KDE code with them.

=== Emacs ===

=== Emacs ===

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The [http://websvn.kde.org/trunk/KDE/kdesdk/scripts/kde-emacs kde-emacs] directory contains a set of key bindings, macros and general useful code. It is compatible with both GNU Emacs and XEmacs.

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The [https://projects.kde.org/projects/kde/kdesdk/kde-dev-scripts/repository/revisions/master/show/kde-emacs kde-emacs] directory contains a set of key bindings, macros and general useful code. It is compatible with both GNU Emacs and XEmacs.

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<!--T:33-->

To start using kde-emacs, add the following to your .emacs:

To start using kde-emacs, add the following to your .emacs:

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</translate>

<syntaxhighlight lang="text">

<syntaxhighlight lang="text">

(add-to-list 'load-path "/path/to/kde-emacs")

(add-to-list 'load-path "/path/to/kde-emacs")

(require 'kde-emacs)

(require 'kde-emacs)

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</code>

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</syntaxhighlight>

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<translate>

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<!--T:34-->

Many settings can be changed by editing the "kde-emacs" group via <tt>M-x customize-group</tt>.

Many settings can be changed by editing the "kde-emacs" group via <tt>M-x customize-group</tt>.

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<!--T:35-->

For more information, including what the key bindings are and what additional settings you could add to your .emacs, please check <tt>kde-emacs.el</tt> itself.

For more information, including what the key bindings are and what additional settings you could add to your .emacs, please check <tt>kde-emacs.el</tt> itself.

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=== Vim ===

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=== Vim === <!--T:36-->

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You can find a vim script in [http://websvn.kde.org/*checkout*/trunk/KDE/kdesdk/scripts/kde-devel-vim.vim kdesdk/scripts/kde-devel-vim.vim] that helps you to keep the coding style correct. In addition to defaulting to the kdelibs coding style it will automatically use the correct style for Solid and kdepim code. If you want to add rules for other projects feel free to add them in the SetCodingStyle function.

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You can find a vim script in [https://projects.kde.org/projects/kde/kdesdk/kde-dev-scripts/repository/revisions/master/raw/kde-devel-vim.vim kde-devel-vim.vim] that helps you to keep the coding style correct. In addition to defaulting to the kdelibs coding style it will automatically use the correct style for Solid and kdepim code. If you want to add rules for other projects feel free to add them in the SetCodingStyle function.

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<!--T:37-->

To use the script, include it in your {{path|~/.vimrc}} like this:

To use the script, include it in your {{path|~/.vimrc}} like this:

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</translate>

<syntaxhighlight lang="text">

<syntaxhighlight lang="text">

source /path/to/kde/sources/kdesdk/scripts/kde-devel-vim.vim

source /path/to/kde/sources/kdesdk/scripts/kde-devel-vim.vim

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</code>

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</syntaxhighlight>

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<translate>

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<!--T:38-->

Document started by Urs Wolfer. Some parts of this document have been adopted from the Qt Coding Style document posted by Zack Rusin on kde-core-devel.

Document started by Urs Wolfer. Some parts of this document have been adopted from the Qt Coding Style document posted by Zack Rusin on kde-core-devel.

You can find a vim script in kde-devel-vim.vim that helps you to keep the coding style correct. In addition to defaulting to the kdelibs coding style it will automatically use the correct style for Solid and kdepim code. If you want to add rules for other projects feel free to add them in the SetCodingStyle function.

To use the script, include it in your ~/.vimrc like this:

source /path/to/kde/sources/kdesdk/scripts/kde-devel-vim.vim

Document started by Urs Wolfer. Some parts of this document have been adopted from the Qt Coding Style document posted by Zack Rusin on kde-core-devel.